Bandopadhyay, P.C. and Carter, Andrew (2017) Mithakhari deposits. In: Bandopadhyay, P.C. and Carter, Andrew (eds.) The Andaman–Nicobar Accretionary Ridge: Geology, Tectonics and Hazards. Memoirs 47. Geological Society, London, pp. 111-132. ISBN 9781786202819.
Abstract
The rocks assigned to the Mithakhari Mélange are composed of conglomerates, gritty and coarse- to fine-grained volcano-lithic to quartzo-feldspathic sandstones, andesitic tuff, siltstone, mudstones, shale, carbonaceous shale and limestones. They occur as coherent and chaotic units as part of the regionally extensive mélange terrane and include olistoliths of pre-ophiolite metasedimentary rocks, ophiolitic ultramafics and basalts, and pelagic-hemipelagic sediments. This chapter describes and assesses the established lithostratigraphic units and examines their palaeontology, geochemistry and geochronology. Focusing on the units with a strong arc signature we consider environments of deposition and palaeogeography. We confirm the existence of active andesite volcanism on the arc massif located east of Andaman arc on the western margin of the Burma–Thai–Malaya peninsula during the Eocene–Oligocene, before the opening of the Andaman Sea in the mid-Miocene, and argue that the Namunagarh Grit, dominated by pyroclast-rich gravity flows, should be treated as a separate unit in studies of Tertiary stratigraphy of Andaman Island. Consideration of the other established units (Hope Town conglomerate and Lipa Shale) suggest these associated rocks types are localized, commonplace and unlikely to be stratigraphically related.
Metadata
Item Type: | Book Section |
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School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
Depositing User: | Andy Carter |
Date Deposited: | 27 Feb 2017 09:38 |
Last Modified: | 02 Aug 2023 17:31 |
URI: | https://eprints.bbk.ac.uk/id/eprint/18116 |
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